The accuracy of the northern and southern edges of the eclipse path are limited to approximately 1-2 kilometers due to the lunar limb profile.
For eclipses five centuries or more centuries in the past or future, the largest uncertainty in the predictions is caused by fluctuations in Earth's rotation due primarily to the tidal friction of the Moon.
The resultant drift in apparent clock time is expressed as ΔT and is is based on the work of Morrison and Stephenson [2004].

The Gregorian calendar is used for all dates from 1582 Oct 15 onwards.
Before that date, the Julian calendar is used (see Calendar Dates).